#for art

i'll start with Stan, just because it'll let me explain what I mean the easiest. Stan has only 2 sources for his eyes according to the wiki (which I'm referencing for all of these), and they contradict each other. In 'A Very Crappy Christmas', Stan specifies he has blue eyes. However, in 'Good Times with Weapons', he has brown eyes. Personally, I trust the first source more than 'Good Times with Weapons' just because that one has anime cutscenes. It makes more sense to me to do it that way. So I don't take 'Good Times with Weapons''s eye colors as canon.

Kyle is a little more complicated though, because his only source for eye color IS 'Good Times with Weapons'! So I just believe it. Plus, I think brown eyes look best on Kyle. It also makes the eye colors of the boys more different.

Kenny's is really interesting in my opinion. It's pretty much always blue, but the movie calls his eyes hazel. While these seem contradictory at first, it reminds me a lot of myself! All my life, I've heard my eyes be called a blue and hazel. So I think of his eyes of being similar to mine. They're blue with a gold/amber splotch near/around the pupil. That being said, I'll usually draw Kenny with purple eyes (From the Black Friday arc). I could see it going either way between those two

My favorite piece of south park 'lore' to drop to friends who havent watched the whole show like I have is that Cartman stole Kenny's eyes. I can't find it on the wiki anymore, but I could have SWORN that there's mention of Cartman having brown eyes early in the show. But I also remember that episode being before the one where Cartman gets his eyes transplanted. So his eyes are the same blue-with-gold color that I consider Kenny's 'original' eye color. (I tend to keep Kenny's eyes purple for much the same reason that Kyle's are brown). I've seen a lot of drawings with Cartman having heterochromia, and I've heard it's because of the eye transplant, but when Cartman is seen with glasses before that eye transplant both eyes are magnified. This implies that both eyes are bad, and only replacing one eye would mean Cartman still needs glasses.

(As an aside to the above paragraph, it really makes me laugh that post-covid Cartman needs glasses when the whole point of him taking Kenny's eyes was to avoid them. It's 100% my headcanon for highschool Cartman and Kenny that they both need glasses, and that Kenny wears contacts.)

As a bonus, let's talk Tweek and Craig. They're the only other two characters I've liked/drawn enough to care about this stuff with. Tweek, according to the wiki, doesnt have any eye color sources. I disagree, as in Tweek and Craig's ult in The Fractured but Whole we see eye colors. Craig has this as well as 'Good Times with Weapons', which I consider less canon than the TFBW ult. For the uninitiated, in that ult, Craig has green eyes and Tweek has blue eyes. I prefer this artistically as well because Craig already has plenty of blue in his design.